Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quantas cadeiras o líder Raymond McCartney tem?
 ###Tabelas: CREATE TABLE men's_singles (men's_singles_id AUTO_INCREMENT PRIMARY KEY, Sd INT, Rk INT, Player VARCHAR, Points INT, Points defending INT, Points won INT, New points INT, Status VARCHAR) CREATE TABLE largest_generating_stations (largest_generating_stations_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Name VARCHAR, Capacity ( MW ) INT, Province VARCHAR, Type VARCHAR) CREATE TABLE men's_50_km (men's_50_km_id AUTO_INCREMENT PRIMARY KEY, Winner VARCHAR, Country VARCHAR, Winter Olympics INT, FIS Nordic World Ski Championships VARCHAR, Holmenkollen VARCHAR) CREATE TABLE results_by_team (results_by_team_id AUTO_INCREMENT PRIMARY KEY, Club VARCHAR, Winners INT, Last final won VARCHAR, Runners-up INT, Last final lost VARCHAR) CREATE TABLE leaders_in_the_northern_ireland_assembely (leaders_in_the_northern_ireland_assembely_id AUTO_INCREMENT PRIMARY KEY, Leader VARCHAR, Party VARCHAR, Leader's Seat VARCHAR, Number of Seats INT, Leader since VARCHAR)  
SELECT SUM Number of Seats FROM leaders_in_the_northern_ireland_assembely WHERE Leader = raymond mccartney